Ronaldo met with Dutch specialist Professor Niek van Dijk in Amsterdam today after Madrid confirmed there had been no improvement in the ankle injury that has kept the winger sidelined for over a month.

Van Dijk, who operated on the 24-year-old's right ankle in the summer of 2008, advised Ronaldo to continue his treatment before returning for a fresh evaluation in 15 days' time.

That means the £80million man is likely to miss both of Portugal's World Cup play-off matches against Bosnia-Herzegovina, with the first leg taking place in Lisbon on November 14 and the return meeting scheduled for Zenica four days later.

Ronaldo is also set to miss a number of matches for Madrid, including this weekend's derby with Atletico, next week's Copa del Rey return leg with Alcorcon, and, depending how the injury progresses, possibly the 'clasico' against Barcelona at the Nou Camp on November 29.

Ronaldo first sustained the problem during the Champions League match against Marseille in September and then aggravated it while playing for Portugal against Hungary, forcing him to miss Madrid's last seven matches - of which the Spanish giants have won just two.

Madrid had previously won all seven of their competitive matches at the start of the season, with Ronaldo playing in all of them and scoring nine goals.

Madrid are one point behind leaders Barcelona at the top of the Primera Division heading into this weekend's 10th round of fixtures.